Is CVE-2026-63475 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-63475 being exploited in the wild.

How severe is CVE-2026-63475?

Medium severity, with a CVSS score of 4.3, published 3 November 2026.

Which products and versions are affected?

Isomorphic-Git before 1.38.6; isomorphic-git (npm) <= 1.38.5, SEMVER:introduced=0,fixed=1.38.6.

Is there a fix for CVE-2026-63475?

Yes. isomorphic-git (npm): upgrade to 1.38.6 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-63475 attacked?

It is attacked over the network or from the adjacent network, in a software library.

Am I affected by CVE-2026-63475?

Check whether you run Isomorphic-Git or isomorphic-git (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-63475: isomorphic-git circular symref denial of service

Q: Is there a fix for CVE-2026-63475?

Yes. isomorphic-git (npm): upgrade to 1.38.6 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-63475 attacked?

It is attacked over the network or from the adjacent network, in a software library.

Q: Am I affected by CVE-2026-63475?

Check whether you run Isomorphic-Git or isomorphic-git (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-63475 · Severity: medium · CVSS 4.3 · Published 2026-11-03

isomorphic-git is a JavaScript Git implementation used in Node.js and browser applications. After cloning from a malicious Git repository, circular symbolic references can be persisted on disk, causing Git operations to hang indefinitely without terminating. This leaves the repository permanently unusable and causes a persistent denial of service.

Technologies: Isomorphic-Git, isomorphic-git (npm). Vendors: Isomorphic-Git, npm.

Quick answers

Is CVE-2026-63475 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-63475 being exploited in the wild.
How severe is CVE-2026-63475?: Medium severity, with a CVSS score of 4.3, published 3 November 2026.
Which products and versions are affected?: Isomorphic-Git before 1.38.6; isomorphic-git (npm) <= 1.38.5, SEMVER:introduced=0,fixed=1.38.6.
Is there a fix for CVE-2026-63475?: Yes. isomorphic-git (npm): upgrade to 1.38.6 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-63475 attacked?: It is attacked over the network or from the adjacent network, in a software library.
Am I affected by CVE-2026-63475?: Check whether you run Isomorphic-Git or isomorphic-git (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

isomorphic-git (npm): upgrade to 1.38.6 or later
```
npm install isomorphic-git@1.38.6
```

Technical details

The vulnerability exists in GitRefManager.resolve() which follows symbolic references without cycle detection or a depth limit. A remote server can supply circular symref= capabilities through updateRemoteRefs that are persisted locally. An attacker performing a man-in-the-middle attack or hosting a malicious repository can trigger this condition; the affected operations (log, status, checkout, branch) do not require authentication or user interaction beyond the initial clone.

Affected products

isomorphic-git isomorphic-git before 1.38.6

Identifiers

CVE-2026-63475
GHSA-96wc-2m84-2cj7

Timeline

2026-11-03: disclosed
2026-07-01: patched

References

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